Unaudited Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Current assets
Cash and cash equivalents	$ 92,554	$ 133,930
Available for sale securities	135,061	155,348
Due from Novartis Pharma AG	3,531	3,531
Prepaid expenses and other current assets	4,650	3,078
Total current assets	235,796	295,887
Property and equipment, net	2,473	3,281
Other assets	3	462
Total assets	238,272	299,630
Current liabilities
Accrued research and development expenses	27,955	47,240
Accounts payable and accrued expenses	8,657	12,032
Deferred revenue	6,646	6,646
Total current liabilities	43,258	65,918
Deferred revenue, long-term	201,669	203,330
Royalty purchase liability	125,000	125,000
Total liabilities	369,927	394,248
Stockholders’ deficit
Preferred stock - $0.001 par value, 5,000,000 shares authorized, no shares issued or outstanding	0	0
Common stock - $0.001 par value, 200,000,000 shares authorized, 35,820,389 and 35,733,276 shares issued and outstanding at March 31, 2017 and December 31, 2016, respectively	36	36
Additional paid-in capital	510,612	504,517
Accumulated deficit	(642,081)	(598,959)
Accumulated other comprehensive loss	(222)	(212)
Total stockholders’ deficit	(131,655)	(94,618)
Total liabilities and stockholders’ deficit	$ 238,272	$ 299,630